Building and using Openwince's JTAG Tools

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Revision as of 14:21, 10 August 2006 by Dtaylor (Talk) (Flash Files)

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This page is under construction and may contain mistakes or have missing information. Use of this information is at your own risk and may further damage your hardware. YOU HAVE BEEN WARNED


There is a possibility that you could brick your NAS with these instructions. Please make sure that you read the entire page carefully. There is also the possibility that you could unbrick your Kurobox with these instructions.

Building JTAG tools

Building the JTAG tools varies depending on the platform you use. Refer to Umino's installation page (in Japanese) or The Google translation of the page for building and installation instructions for several popular flavors of Linux.

In general, you need to move into the include directory and do a ./configure and make install and then move into the jtag directory and do a ./configure, make, and make install as root. You will also need to copy the data/motorola/mpc8241 directory to /usr/local/share/jtag/.

You can start JTAG tools with the command "jtag".

JTAG tools command sequence to flash the bootloader

The following are the commands to prepare the Kuro for data transfer. This sequence assumes you are using one of the JTAG cables described here and it is attached to the primary parallel port.

Start jtag and execute the following commands at the jtag prompt:

jtag> cable parallel 0x378 DLC5
jtag> detect
jtag> include motorola/mpc8241/1.2 
jtag> endian big 
jtag> instruction SAMPLE/PRELOAD 
jtag> shift ir 
jtag> shift dr  
jtag> dr 
jtag> instruction EXTEST 
jtag> shift ir 
jtag> initbus mpc824x 
jtag> detectflash 0xFFC00000 

According to the Flash ROM page, the flash map is as follows:

start Size (HEX) size contents
0xFFF00000 0x070000 448 K bootcode.bin
0xFFF70000 0x010000 64K HDD status (OKOKOK)
0xFFF80000 0x080000 512 K Empty
0xFFC00000 0x300000 3 MB Linux/initrd

To read the bootloader which is stored in the area described as bootcode.bin type:

jtag> readmem 0xFFF00000 0x0070000 bootloader 

To write the bootloader with file u-boot.bin type:

jtag> flashmem 0xFFF00000 u-boot.bin

Flash Files

Flash files are available at Use these at your own risk.